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New Member

2960S - FlexStack module Auth failed

I have been trying to make a stack with two 2960S. They have the same IOS but they behave as they were not connected.

One is in production and I am attaching a brand new one to it; in the one that is in production I get these 2 messages:

FlexStack Module SmartChip Authentication Failed

Jun  1 16:54:27.984 GMT-5: %ILET-1-DEVICE_AUTHENTICATION_FAIL: The FlexStack Mod

ule inserted in this switch may not have been manufactured by Cisco or with Cisc

o's authorization. If your use of this product is the cause of a support issue,

Cisco may deny operation of the product, support under your warranty or under a

Cisco technical support program such as Smartnet.  Please contact Cisco's Techni

cal Assistance Center for more information.

I tried switching the modules and the outcome is the same, so I think the modules are ok.

What to you recommend, is there a way to bypass this authentication?

Thanks for your help,


Hall of Fame Super Gold

Re: 2960S - FlexStack module Auth failed

Hmmm ...

I've seen this before and I've fixed this (several times) but you do you really want to know how I did this?

Power down the switch and re-insert the stacking module is one method.  Make very sure the s_crews are secure (and not just finger-tight).  If the error message returned, I would power down the switch, remove the stacking module and WHACK the flat side of the stacking module on a surface (NOT the intention of breaking the module) and re-inserting the module back.

I pray you don't have to result in the 2nd method.

New Member

2960S - FlexStack module Auth failed

A firmware update did the trick for me.

Re-seating the module didn't work and I didn't try whacking it off of my desk.

New Member

2960S - FlexStack module Auth failed

What version were you running and what version did you upgrade to?  I am having the same issue while running 122-55.SE2


New Member

2960S - FlexStack module Auth failed

I upgraded to 15.0(2). I'm not sure what version I was on before.

Even after the IOS upgrade I still had one faulty module that I had to return. I probably had four modules total give me grief and the IOS upgrade fixed all but one of them.

New Member

2960S - FlexStack module Auth failed

The version I was using is


New Member

2960S - FlexStack module Auth failed

Fortunately, I had another switch so I installed those and I am migrating the connections to this new pair of switches. I think a reload would have help, but this switch is in production.


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